Steam-pressure gage



(Mode=1.)

^ J. BURRELL,

Steam Pressure Gage. i

No. 237,243.- Patented Feb, 1,' 1881.

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JPETERS, PHOTD-IITNOGRAPHER, WASEINGTON D c a front view of the interierof my improved` UNITED STATES i PATENT OFFICEO J ARVIS BURRELL, OF 'EASTBRIDGEWATER, ASSIGNOE TO GEORGE H. P. FLAGG, OF BOSTON, 'MASSACHUSETTSSTEAM- PRESSU RE GAG E.

SPECIFIGATION forming parttof Letters Patent No. 237,243, dated February1, 1881.

Application filedseptmber 24, 1880. (Model) To all whom it may concernBe it known that I, JARVIS 'BURRELL,`O" East Bridgewater, in thecountyot' Plymouth I and State of Massachusetts, have invented certainImprovements inSteam-Gages, of I which the following is aspecification.

Figure 1 ot' the accompanyingdrawings is gage. Fig. 2 is a centraltransverse vertical section ot' the same. Figs. 3 and bare 'respectivelya side and front view of parts, in

detail, of my invention.

The object of the present invention is to effect certain new and usefulimprovements `in stean or pressure gages, but more particularly toobviate objections in an invention of` like nature for which LettersPatent No.-10l,636 were granted to James W. Maloy, April 5, 1870. In thepatented invention referred toinaccuracy in the operation of the gage isapt tooccur, mainly owing to thedependency of the lever for its actionon separate bearings or fulcrums-that is, the-stem of the button, whichis movable and subject to slight variation, is very liable to vary inits `distance from the fixed knife-edge or fulcrum on which the levervibrates, thereby causing an nncertainmeasurement of the pressure; and,further, the curved spring is weakened so as to frequently break byhaving an aperture formed through its center to admit the sten of thebutton, and the ends of the spring are made to abut at the joints of thecasting, which is liable to give way and forms a movable and uncertainbearing.

These objectons are obviated by my improvements, which consist, mainly,of a lever having knife-edge fnlcrums and hearing cast in one piece withit, and arranged, as will be hereinafter more fully described, to beoperated by one action.

These improvements otherwise consist in varying the construction ofseveral of the devices of the gage to perform their required functionsin a more perfect manner, all of which I will now proceed to desoribe.

In the drawings, A represents a metallic casing having a glazedscrew-cover, B, and a suitably-marked dial-plate, G, and having attachedwithin a triangular metallic frame, E, formed with bottom projectingplates, E screwed to the top of the vertical sides of a The screw-head His formed with a central aperture opening into the chamber b and eX-tcnding throughan outward stem or steam or pressure tube or pipe, H'.Theinteriorsides of the casting F are notched or grooved laterally at fto receive and firmly hold the ends of a conoavely-cnrved spring, I,which passes through a transverse slot, o, of ayoke, lK,whose bottom orbutton-like portion abutson the top, so as to receive the action of thedisk or plate Gr; and the top of the yoke is curved upward from the endsto form a central bearinor seat for the knife-edge of an` arm, l,projecting forward of and centrali between lateralextending arms orfulorums l' ourving downward from on either side of a vertical lever, L,and each fulcrum formed with an upper knife-edge bearin g in grooves'formed in the bottom of a hearing or plate, M, projecting at a rightangle from the bottom of the frame E` and cut out in the center of itslower portion to admit the projection of the center arm, l.

Connected with the top of the lever L is a segmental ratchet-bar, N,whose teeth mesh with a pinion, n, turning in abearing., O, slot `ted toreceive and allow the action of the ratchet IOO H' into the chamber b,acts on the plate or disk G and bears it` against the button or bottomportion of the yoke K, which is raised thereby and bears up the arm l,which vibrates partially the lever L, whose lateral arms or fulcrums l'act in the grooved or notched bottom of the hearing M and actuate theratchet and pinion and operate the index over the dialplate to the pointdetermined by the amount of pressureexerted. The spiral spring t servesto secure the required tension to the lever L, and the spring I suppliesthe required tension to the yoke K.

By means ot' the regulating screw stem or pin 7' the distance of thethrow of the lever may be varied to regulate the movement of the index,so that it shall always start from the zero or starting point.

By the above description, reference being .made to the drawings, it willreadily be seen that the action of the lever must be accurate under anyvariation ot' prcssure or circumstances, as its bearingand fulcrums areformed on it, and there is nothing to vary their distances, as there isin the previous invention, where the lever turns on a fixed ful'crumconnected with the frame, and its bottom arm bears on a movable hearingor fulcrum forned by the stern of the button.

By the regulating-stem r the lever may be adjusted in its movement toalways start the indexfrom the required point, thereby preventinginaccuracy in the measurement, otherwise liable to occnr by the indexbeing carried beyond or not quite to the startin g-point.

By extending the spring I through the yoke K the weakness occasioned bythe aperture for the button-stern in theinvention is prevented; and bynotchiug the sides of the casting F to receive the ends of the spring I,instead of abutting the ends at thejoints of the casting, as heretoforementioned, the spring is more securely and steadily'held and moreaccurate in its operation.

By my improvements I insure a more perfect operation without incrcasingthe expense of the gage.

A steam-gage has leretofore been made in which the index-moving leverhas been provided with a removable or separable pivot to rest upon thediaphragm below, and apin extended through its lower end, on both sides,to engage notohes in a casting from above.

Having thus described my improvements, what I claim as my invention, anddesire to have secured to me by Letters Patent, is

1. In a steam-gage'having a fiexible disk, Gr, and a movable yoke, K,resting upon said disk, a lever, L, for Operating the index, cast in onepiece with a central extension, Z, having its hearing upon themovableyoke, and laterally-projecting arms l' l', combined With thecasting M, against which said arms bear. substantially as shown anddescribed.

2. In a steam-gage, the disk Gr, the yoke K,

loosely placed thereupon, the hearing F,-

ings M, the one-piece furcated lever L, and an index or indicatingmechanism, combined and arranged to operate substantially as described.

3. The disk G, the yoke K, loosely placed thereupon, the inperforatespring l and its bearings F, for supporting the yoke, the beariugs M,the forked lever L, and an index or indicating mechanism, combined andarranged substantially as described.

In testimony whereofI have signed my name to this specification, in thepresence of two subscribing witnesses, this 2lst day of September, A. D.1880. e

JARVIS BURRELL.

Witnesses O. F. BROWN, J osEPH F. BALDWIN.

